A.J.
Why wean from a bed or nap time bottle now?? I would wait a little while. My 2 year old still takes a nap and bet time bottle and my other 2 kids did when they were that age and are fine...
but if you must... add a little water, replacing the milk each day until you are finally just have water then she will probably not want it... and if she does its just water... then replace bottle with a sippy cup of water and at least she has soemthing to drink if she is thirsty.
hth
A. J